A day after President Obama became the first holder of the Oval Office to endorse same-sex marriage, presumptive Republican nominee Mitt Romney is being accused of bullying a student believed to be gay as a teenager in the 1960s.

The Washington Post—citing five of Romney’s fellow students at the Cranbrook School in Bloomfield Hills, Mich.—reported Thursday that Romney led a posse that pinned down another boy while Romney, himself, cut the boy’s bleached-blond hair, which usually draped over one eye.

The alleged incident occurred in 1965, when Romney was a senior. The target was a junior named John Lauber, whom the Post report described as “soft-spoken” and “perpetually teased for his nonconformity and presumed homosexuality.”

Advertisement - Continue Reading Below

Mathew Friedemann, a Romney friend and dorm-mate, told the Post that Romney complained often about Lauber’s appearance.

Friedemann claimed that one day Romney and a group of boys sought out Lauber, tackled him and held him to the ground while Romney clipped the locks he found offensive. Three other former Cranbrook students corroborated the story on the record, and a fourth spoke to the Post anonymously.

A Romney campaign spokeswoman told the Post that Romney does not recall such an attack.

“Anyone who knows Mitt Romney knows that he doesn’t have a mean-spirited bone in his body,” Andrea Saul said in a statement. “The stories of 50 years ago seem exaggerated and off base, and Governor Romney has no memory of participating in these incidents.”

But during a Thursday-morning interview with conservative radio host Brian Kilmeade, Romney offered a vague apology.

“Back in high school, I did some dumb things, and if anybody was hurt by that or offended by that, I apologize,” he said.

Romney did not acknowledge the specific incident reported by the Post but said that he “participated in a lot of hijinks and pranks in high school, and some of them might have gone too far.”

Romney added that he is “quite a different guy now.”

Callum Borchers can be reached at callum.borchers@globe.com. Follow him on Twitter @callumborchers.